Red Hat made its fortune selling licenses with support contracts for software to risk-averse industrires. That the software happened to be free wasn't really relevant to the revenue stream except insofar as it made it cheaper for Red Hat to provide the service.

I don't see how a desktop X server is going to tap into that need.

I mean... I've been using and relatively happy with the Cygwin X server integration for more than a decade. I'm not about to drop $50 on a polished replacement.